Silver halide emulsion containing an azo-pyrazolone coupler



United States Patent 3,476,564 SILVER HALIDE EMULSION CONTAINING ANAZO-PYRAZOLONE COUPLER Brunello Mariani, Milan, Alberto Guizzi,Ferrania,

Savona, and Eugenio Tisselli, Milan, Italy, assignors to Ferrania,S.p.A., Milan, Italy N0 Drawing. Filed May 3, 1966, Ser. No. 547,189

Int. Cl. G03c 1/04 US. Cl. 96-100 6 Claims ABSTRACT OF THE DISCLOSURE Aphotosensitive silver halide emulsion is shown which contains at leastone colored azo coupler of the formula wherein Y is hydrogen, halogen orcarboxyl, X is halogen or carboxyl, and R is an aryl radical having atleast one water-solubilizing group and at least one group impartingnon-diffusivity to the coupler.

This invention relates to novel compounds and their use as colorcouplers in color photography.

It is known that colored images produced in multilayer filmconstructions by chromogenic development often results in unsatisfactorycolor rendition due to secondary absorptions by the image-formingindophenol or azomethine dyes. Correction is normally accomplished bythe use of colored masks which are produced during the chromogenicdevelopment, such masks being provided by using colored couplermaterials. For example, whereas colorless couplers of the alpha-naphtholtype provide a blue image on a colorless background, colored couplers ofthe 4-phenylazo-1-naphthol type provide blue images on an orange ormagenta background. Likewise, whereas colorless couplers of thepyrazolone type produce magenta images on a colorless background,colored couplers of the 4-phenylazo-pyrazolone type produce magentaimages on a yellow background. Further information on the mechanism ofsuch reactions and on masking technology can be obtained from Vittum,Sawdey, Herdle and School, J.A.C.S. 72, p. 1533 (1950); Vittum andBrown, J.A.C.S. 68, p. 2235 (1946); Evans, Hanson Jr. and Brewer,Principles of Color Photography, p. 565 and fol.

One of the problems encountered with the use of colored couplers is adecreased reactivity in the coupling reaction as compared withcorresponding colorless coupler. As a result, sensitivity is decreased,often to the point of rendering the colored coupler essentially useless.The low reactivity of such colored couplers appears to be an "iceintrinsic characteristic of the colored azo coupler compounds, perhapsdue to either the structure of the original colorless coupler or thestructure of the diazotized molecule used to obtain the azo dye or tothe entire structure of the moieties joined by the azo radical. Thislower reactivity is observed most frequently in colored couplers of the4-arylazo-pyrazolone class which correspond to the formula In Us. PatentNo. 2,983,608 colored pyrazolone coupler compounds are described which,because of certain substitution on the pyrazoline ring, are stated to besufficiently reactive to provide compensation for unwanted blueabsorption of the magenta dye produced upon color development. However,considerable improvement in reactivity of colored couplers withoutlowering the molar extinction coefficient has been desired.

It is therefore an object of this invention to provide new coloredcouplers having relatively high coupling reactivity.

Other objects and advantages will be apparent from the followingdescription.

In accordance with this invention it. has been found that coloredcouplers having the aforementioned advantages are represented by thestructural formula wherein Y is hydrogen, halogen (e.g. chlorine,bromine), or carboxyl, X is halogen or carboxyl, and R is hydrogen,alkyl (e.g. C C alkyl) or aryl (including substituted aryl, e.g.substituted phenyl). Preferably R is an aryl radical having a Watersolubilizing group (e.g. carboxylic acid or salt thereof, sulfonic acidor salt thereof, sulfamidic group, etc.) and a group impartingnon-dilfusibility and substantivity (e.g. long chain or C -C alkylcarboxamido groups, etc.). Such couplers are particularly characterizedby their high degree of reactivity in the chromogenic developmentreaction. Of particular value are those couplers in which R comprisesp-phenylsulfonamidophenyl.

The high molar extinction coefficient of this class of yellow dyes canbe illustrated by comparing one of the preferred dyestuffs of thisinvention with well known colored couplers. The colored coupler COOH lIHCOCnHu exhibits a molar extinction coefiicient in butyl acetate of238x10 whereas the coupler ethyLp-phenylenediamine developer. Thecharacteristics O5Hn(tertiary) (III) have a corresponding molarextinction coefficient in butyl acetate of l.89 and 2.31 x 10respectively. The Coupler II is of the well known 3-acylamino-pyrazolonetype, and the Coupler III is of the l-phenyl-3-anilinopyrazolone type.Pyrazolone compounds of the type exemplified by II and III have beenconsidered in Us. Patent No. 2,983,608, including their molar extinctioncoefficients. Comparison of these molar extinction coeflicientsindicates that the colored couplers of the present invention alsodisplay a high value for the molar extinction coefficient andaccordingly can be used in relatively small quantities in thephotographic emulsion. Moreover, it is alternatively possible to use thecolored couplers of this invention in thinner layers, thereby permittinggreater definition and improved resoltuion of the photographic material.

The colored couplers of this invention are particularly suitable for usein negative-type color photographic materials capable of yielding, byprinting on paper or color positive film, faithful reproduction of theoriginal image with good saturation and improved sharpness. These colorcouplers may be employed as the only coupler material in aphotosensitive layer, or they may be used in admixture with colorlesscouplers to further control the masking effect.

By exposing to a light image a sample of a silver halide photographicmaterial comprising an emulsion layer which is sensitized to green lightand which contains a color coupler of this invention, a magenta colorednegaof the resulting magenta dye are essentially the same as describedin Italian Patent No. 632,532, since the same dye is formed.Superimposed on the magenta colored negative image is a yellow coloredpositive image of the original subject, representing the masking imagewhich, upon printing from the negative using suitable filters,compensates for the undesirable light absorption of the magenta dye.

The following examples illustrate the preparation of the coloredcouplers of this invention, it being understood that they are presentedfor purposes of illustration and not of limitation.

EXAMPLE 1 77.5 grams of l-p-(3'-carboxy-5-stearoylaminophenylsulfamyl)-phenylcarbamyl-3-anilino-5 pyrazolone weredissolved in 900 ml. of water and ml. of 36 Baum caustic soda. Thissolution was neutralized using thiazole yellow as indicator and 40 gramsof sodium carbonate. To this solution, stirred and cooled to 0 C., wasadded over a period of one-half hour an aqueous solution of thediazonium salt from 14.3 grams of 2-chloro-4-aminophenol. Stirring wascontinued until the reaction was complete, and the mixture was acidifiedwith hydrochloric acid, using Congo red as indicator. The product wasthen recovered by filtration, was washed to neutrality with cold water,and was then crystallized from acetic acid. The colored product had theformula:

COOH

NHCO 0 7E 5 N (calculated) 12.05%. N (found) 11.39%. Absorption peak indimethylformamide 410 millimicrons.

EXAMPLE 2 Following the procedure of Example 1, with the substitution ofa solution of the diazonium salt obtained from 19 grams of2-brorno-4-arninophenol for the diazonium salt of2-chloro-4-aminophenol, the following colored coupler was obtained:

1 00 N Br N (calculated) 11.51%. N (found) 11.39%. Absorption peak indimethylformamide 410 millimicrons.

COOH

EXAMPLE 3 Following the procedure of Example 1, with the substitution ofa solution of the diazonium salt obtained from 22.4 grams of2,6-dichloro-4-aminophenol for the diazonium salt of2-chloro-4-aminophenol, the following colored coupler was obtained:

(Ill

N (calculated) 11.66%. N (found) 11.0%. Absorption peak indirnethylformamide 410 millimicrons.

EXAMPLE 4 Following the procedure of Example 1, with the substitution ofa solution of the diazonium salt obtained from 26.6 grams of2,6-dibromo-4-aminophenol for the diazonium salt of2-chloro-4-aminophenol, the following colored coupler was obtained:

6 N (calculated) 10.56%. N (found) 10.31%. Absorption peak indimethylformamide 410 millimicrons.

EXAMPLE 5 Following the procedure of Example 1, with the substitution ofa solution of the diazonium salt obtained from 15.3 grams of5-aminosalicylic acid for the diaoONH-Q-Sm-NH-Q COOH zonium salt of2-chloro-4-aminopheno1, the following colored coupler was obtained:

1 COOH $0 1 1 NBC 0 0 7113 COOH What is claimed is: 1. A photosensitivesilver halide emulsion layer con- 50 taining a colored azo couplerhaving the formula COOH wherein Y is hydrogen, halogen or carboxyl, X ishalo- 5. The emulsion of claim 1 wherein said colored azo gen orcarboxyl, and R is a p-phenylsulfonamidophenyl coupler has the formula6. The emulsion of claim 1 wherein said colored azo radical having atleast one water-solubilizing group and at least one group impartingnon-diflusivity to the coupler coupler has the formula 2. The emulsionof claim 1 wherein said colored azo coupler has the formula 3. Theemulsion of claim 1 wherein said colored azo coupler has the formula iO=C N Br NHCOOn as I COOH 4. The emulsion of claim 1 wherein saidcolored azo coupler has the formula References Cited UNITED STATESPATENTS 2,455,170 11/1948 Glass et a1. 969 3,227,551 1/1966 Barr et a1.96100 FOREIGN PATENTS 632,532 1/1962 Italy.

J. TRAVIS BROWN, Primary Examiner US. Cl. X.R. 969

NH C O C Has COOH COOH

1 NBC 0 CnHar UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 3, +76,56 Dated November 4, 1969 Brunello Mariani, Invent r(Alberto Guzzi and Eugenio Tisselli It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

In the heading second inventor's name should be --Guzzi--, instead of"Guizzi Column 1, line &7, "School" should be --Scho1l-;

Column 2, line 18, pyrazoline" should be --pyrazolone-;

Column 2, bottom, the diagram should be labelled --(I);

Column 3, diagram, "(1)" should be --(II)--;

Column 3, diagram, "(11)" should be --(III)--;

Column 3, diagram, "(111) should be deleted.

Column 7, Claim 2, first ring in structure,

H II

HO N should be HOQN Signed and sealed this 25th day of April 1972.

(SEAL) Atte st EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting OfficerCommissioner of Patents FORM PO-105O {IO-69] USCOMM-DC 603764 69

